Lubricating oil compositions having functionalized quercetin antioxidants

ABSTRACT

This disclosure provides a method for improving or maintaining antioxidant performance of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one functionalized quercetin antioxidant, as a minor component. The at least one functionalized quercetin antioxidant is soluble in the lubricating oil. Antioxidant performance is improved or maintained as compared to antioxidant performance achieved using a lubricating oil containing a phenolic or aminic antioxidant, as determined by Lubricant Oxidation Test as described herein or Catalytic Oxidation Test as described herein. This disclosure also relates to lubricating oils having at least one functionalized quercetin antioxidant. The lubricating oils are useful as passenger vehicle engine oils (PVEO), commercial vehicle engine oils (CVEO), and other mechanical industrial applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/779,607 filed Dec. 14, 2018, which is herein incorporated byreference in its entirety.

FIELD

This disclosure relates to a method for improving or maintainingantioxidant performance of a lubricating oil in an engine or othermechanical component lubricated with the lubricating oil by using alubricating oil having at least one functionalized quercetinantioxidant. This disclosure also relates to lubricating oils having atleast one functionalized quercetin antioxidant. The lubricating oils ofthis disclosure are useful in internal combustion engines, and othermechanical industrial applications.

BACKGROUND

Antioxidants are added to lubricants to prevent oxidative degradation inservice. Such degradation may result in deposits on metal surfaces, thepresence of sludge, or a viscosity increase in the lubricant. A widevariety of oxidation inhibitors are known that are useful in lubricatingoil compositions.

Current antioxidant chemistry is mostly based on hindered phenols andalkylated aromatic amines. Hindered phenols and alkylated aromaticamines have been successfully practiced by the lubricant industry formany decades. Current antioxidant technology satisfies performancerequirements. However, an improvement of the technology environmentalsustainability would be desirable to increase the appeal of futurelubricant products.

Quercetin is a naturally occurring compound known for its biologicalactivity as an antioxidant. It is a polyhydroxy phenol with limitedsolubility in water and in oil. It would be desirable to improve itssolubility in lubricating oils, and at the same time boost its activityas antioxidant in lubricating oils.

Despite advances in lubricant oil formulation technology, there exists adesire for an engine oil lubricant that effectively improves lubricantantioxidizing performance, including solubility of the antioxidant inlubricant oils, without negatively affecting other lubricant properties.

SUMMARY

This disclosure relates in part to a lubricating oil having acomposition comprising a lubricating oil base stock as a majorcomponent, and at least one functionalized quercetin antioxidant, as aminor component. The functionalized quercetin antioxidant has thefollowing

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

The at least one functionalized quercetin antioxidant is soluble in thelubricating oil. Further, in an engine or other mechanical componentlubricated with the lubricating oil, antioxidant performance is improvedor maintained as compared to antioxidant performance achieved using alubricating oil containing a phenolic or aminic antioxidant, asdetermined by Lubricant Oxidation Test as described herein or CatalyticOxidation Test as described herein.

This disclosure also relates in part to a method for improving ormaintaining antioxidant performance of a lubricating oil in an engine orother mechanical component lubricated with lubricating oil by using asthe lubricating oil a formulated oil. The formulated oil has acomposition comprising a lubricating oil base stock as a majorcomponent, and at least one functionalized quercetin antioxidant, as aminor component. The functionalized quercetin antioxidant has thefollowing structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

This disclosure further relates in part to a composition comprisingfunctionalized quercetin. In particular, the functionalized quercetinhas the following structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

This disclosure still further relates in part to a process for preparingfunctionalized quercetin. In an embodiment, the process involvesesterifying or etherifying quercetin under reaction conditionssufficient to prepare the functionalized quercetin. In anotherembodiment, the functionalized quercetin has the following structuralformula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

It has been surprisingly found that, in accordance with this disclosure,improvements in antioxidation performance are obtained in an engine orother mechanical component lubricated with a lubricating oil, byincluding at least one functionalized quercetin antioxidant, in thelubricating oil.

Also, it has been surprisingly found that the functionalized quercetinantioxidant is soluble in lubricating oils, and at the same timeexhibits enhanced activity as an antioxidant in lubricating oils.

In particular, it has been surprisingly found that, in accordance withthis disclosure, in an engine or other mechanical component lubricatedwith the lubricating oil, antioxidant performance is improved ormaintained as compared to antioxidant performance achieved using alubricating oil containing a phenolic or aminic antioxidant, asdetermined by Lubricant Oxidation Test as described herein or CatalyticOxidation Test as described herein.

Further, it has been surprisingly found that, in accordance with thisdisclosure, improvements in antioxidation performance are obtained in anengine or other mechanical component lubricated with a lubricating oil,by including at least one functionalized quercetin antioxidant inconjunction with an aminic antioxidant, in the lubricating oil.

Other objects and advantages of the present disclosure will becomeapparent from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 graphically shows results from the Lubricant Oxidation Test at165° C., 125 cc/min. air in presence of Cu naphthenate, in accordancewith the Examples.

FIG. 2 shows comparative results from the Catalytic Oxidation Test offunctionalized quercetin samples relative to commercial phenolicantioxidant, in accordance with the Examples.

FIG. 3 shows comparative results from the Catalytic Oxidation Test offunctionalized quercetin samples relative to commercial aminicantioxidant, in accordance with the Examples.

FIG. 4 shows the 1H and 13C NMR of Inventive Example 2, in accordancewith the Examples.

FIG. 5 shows the 1H NMR of Inventive Example 3, in accordance with theExamples.

DETAILED DESCRIPTION Definitions

“About” or “approximately.” All numerical values within the detaileddescription and the claims herein are modified by “about” or“approximately” the indicated value, and take into account experimentalerror and variations that would be expected by a person having ordinaryskill in the art.

“Major amount” as it relates to components included within thelubricating oils of the specification and the claims means greater thanor equal to 50 wt. %, or greater than or equal to 60 wt. %, or greaterthan or equal to 70 wt. %, or greater than or equal to 80 wt. %, orgreater than or equal to 90 wt. % based on the total weight of thelubricating oil.

“Minor amount” as it relates to components included within thelubricating oils of the specification and the claims means less than 50wt. %, or less than or equal to 40 wt. %, or less than or equal to 30wt. %, or greater than or equal to 20 wt. %, or less than or equal to 10wt. %, or less than or equal to 5 wt. %, or less than or equal to 2 wt.%, or less than or equal to 1 wt. %, based on the total weight of thelubricating oil.

“Essentially free” as it relates to components included within thelubricating oils of the specification and the claims means that theparticular component is at 0 weight % within the lubricating oil, oralternatively is at impurity type levels within the lubricating oil(less than 100 ppm, or less than 20 ppm, or less than 10 ppm, or lessthan 1 ppm).

“Other lubricating oil additives” as used in the specification and theclaims means other lubricating oil additives that are not specificallyrecited in the particular section of the specification or the claims.For example, other lubricating oil additives may include, but are notlimited to, antioxidants, detergents, dispersants, antiwear additives,corrosion inhibitors, viscosity modifiers, metal passivators, pour pointdepressants, seal compatibility agents, antifoam agents, extremepressure agents, friction modifiers and combinations thereof.

“Hydrocarbon” refers to a compound consisting of carbon atoms andhydrogen atoms.

“Alkane” refers to a hydrocarbon that is completely saturated. An alkanecan be linear, branched, cyclic, or substituted cyclic.

“Olefin” refers to a non-aromatic hydrocarbon comprising one or morecarbon-carbon double bond in the molecular structure thereof.

“Mono-olefin” refers to an olefin comprising a single carbon-carbondouble bond.

“Cn” group or compound refers to a group or a compound comprising carbonatoms at total number thereof of n. Thus, “Cm-Cn” group or compoundrefers to a group or compound comprising carbon atoms at a total numberthereof in the range from m to n. Thus, a C1-C50 alkyl group refers toan alkyl group comprising carbon atoms at a total number thereof in therange from 1 to 50.

“Carbon backbone” refers to the longest straight carbon chain in themolecule of the compound or the group in question. “Branch” refer to anysubstituted or unsubstituted hydrocarbyl group connected to the carbonbackbone. A carbon atom on the carbon backbone connected to a branch iscalled a “branched carbon.”

“SAE” refers to SAE International, formerly known as Society ofAutomotive Engineers, which is a professional organization that setsstandards for internal combustion engine lubricating oils.

“SAE J300” refers to the viscosity grade classification system of enginelubricating oils established by SAE, which defines the limits of theclassifications in rheological terms only.

“Base stock” or “base oil” interchangeably refers to an oil that can beused as a component of lubricating oils, heat transfer oils, hydraulicoils, grease products, and the like.

“Lubricating oil” or “lubricant” interchangeably refers to a substancethat can be introduced between two or more surfaces to reduce the levelof friction between two adjacent surfaces moving relative to each other.A lubricant base stock is a material, typically a fluid at variouslevels of viscosity at the operating temperature of the lubricant, usedto formulate a lubricant by admixing with other components. Non-limitingexamples of base stocks suitable in lubricants include API Group I,Group II, Group III, Group IV, and Group V base stocks. PAOs,particularly hydrogenated PAOs, have recently found wide use inlubricants as a Group IV base stock, and are particularly preferred. Ifone base stock is designated as a primary base stock in the lubricant,additional base stocks may be called a co-base stock.

All kinematic viscosity values in this disclosure are as determinedpursuant to ASTM D445. Kinematic viscosity at 100° C. is reported hereinas KV100, and kinematic viscosity at 40° C. is reported herein as KV40.Unit of all KV100 and KV40 values herein is cSt unless otherwisespecified.

All viscosity index (“VI”) values in this disclosure are as determinedpursuant to ASTM D2270.

All Noack volatility (“NV”) values in this disclosure are as determinedpursuant to ASTM D5800 unless specified otherwise. Unit of all NV valuesis wt %, unless otherwise specified.

All pour point values in this disclosure are as determined pursuant toASTM D5950 or D97.

All CCS viscosity (“CCSV”) values in this disclosure are as determinedpursuant to

ASTM 5293. Unit of all CCSV values herein is millipascal second (mPa·s),which is equivalent to centipoise), unless specified otherwise. All CCSVvalues are measured at a temperature of interest to the lubricating oilformulation or oil composition in question. Thus, for the purpose ofdesigning and fabricating engine oil formulations, the temperature ofinterest is the temperature at which the SAE J300 imposes a minimalCCSV.

All percentages in describing chemical compositions herein are by weightunless specified otherwise. “Wt. %” means percent by weight.

Lubricant Compositions with Quercetin Antioxidants Disclosed Herein

It has now been found that functionalized quercetin antioxidants canprovide equivalent or better performance than commercially availablephenolic or aminic antioxidants. The functionalized quercetinantioxidants show similar activity at lower treat rate, and have beenfound to be particularly effective when used in conjunction with aminicantioxidants as illustrated by the Lubricant Oxidation Test results inan industrial oil formulation.

This disclosure provides various benefits including: improvement inantioxidizing performance obtained in an engine or other mechanicalcomponent lubricated with a lubricating oil, by including at least onefunctionalized quercetin antioxidant, in the lubricating oil; thefunctionalized quercetin antioxidant is soluble in lubricating oils, andat the same time exhibits enhanced activity as an antioxidant inlubricating oils; in an engine or other mechanical component lubricatedwith the lubricating oil, antioxidant performance is improved ormaintained as compared to antioxidant performance achieved using alubricating oil containing a phenolic or aminic antioxidant, asdetermined by Lubricant Oxidation Test as described herein or CatalyticOxidation Test as described herein; and improvement in antioxidizingperformance is obtained in an engine or other mechanical componentlubricated with a lubricating oil, by including at least onefunctionalized quercetin antioxidant in conjunction with an aminicantioxidant, in the lubricating oil.

The lubricating oils of this disclosure provide excellent antioxidantperformance. This benefit has been demonstrated for the lubricating oilsof this disclosure in the Lubricant Oxidation Test as described herein,and the Catalytic Oxidation Test as described herein.

The lubricant compositions of this disclosure provide advantagedantioxidant performance in lubricant compositions, which can include,for example, lubricating liquids, semi-solids, solids, greases,dispersions, suspensions, material concentrates, additive concentrates,and the like.

The lubricant compositions of this disclosure provide advantagedantioxidant performance under diverse lubrication regimes, that include,for example, hydrodynamic, elastohydrodynamic, boundary, mixedlubrication, extreme pressure regimes, and the like.

The lubricating oils of this disclosure are particularly advantageous aspassenger vehicle engine oil (PVEO) products, commercial vehicle engineoil (CVEO) products, and other mechanical industrial applications.

Lubricating Oil Base Stocks

A wide range of lubricating base oils is known in the art. Lubricatingbase oils that are useful in the present disclosure are natural oils,mineral oils and synthetic oils, and unconventional oils (or mixturesthereof) can be used unrefined, refined, or rerefined (the latter isalso known as reclaimed or reprocessed oil). Unrefined oils are thoseobtained directly from a natural or synthetic source and used withoutadded purification. These include shale oil obtained directly fromretorting operations, petroleum oil obtained directly from primarydistillation, and ester oil obtained directly from an esterificationprocess. Refined oils are similar to the oils discussed for unrefinedoils except refined oils are subjected to one or more purification stepsto improve at least one lubricating oil property. One skilled in the artis familiar with many purification processes. These processes includesolvent extraction, secondary distillation, acid extraction, baseextraction, filtration, and percolation. Rerefined oils are obtained byprocesses analogous to refined oils but using an oil that has beenpreviously used as a feed stock.

Groups I, II, III, IV and V are broad base oil stock categoriesdeveloped and defined by the American Petroleum Institute (APIPublication 1509; www.API.org) to create guidelines for lubricant baseoils. Group I base stocks have a viscosity index of between about 80 to120 and contain greater than about 0.03% sulfur and/or less than about90% saturates. Group II base stocks have a viscosity index of betweenabout 80 to 120, and contain less than or equal to about 0.03% sulfurand greater than or equal to about 90% saturates. Group III stocks havea viscosity index greater than about 120 and contain less than or equalto about 0.03% sulfur and greater than about 90% saturates. Group IVincludes polyalphaolefins (PAO). Group V base stock includes base stocksnot included in Groups I-IV. The table below summarizes properties ofeach of these five groups.

Base Oil Properties Saturates Sulfur Viscosity Index Group I <90and/or >0.03% and  ≥80 and <120 Group II ≥90 and ≤0.03% and  ≥80 and<120 Group III ≥90 and ≤0.03% and ≥120 Group IV polyalphaolefins (PAO)Group V All other base oil stocks not included in Groups I, II, III orIV

Natural oils include animal oils, vegetable oils (castor oil and lardoil, for example), and mineral oils. Animal and vegetable oilspossessing favorable thermal oxidative stability can be used. Of thenatural oils, mineral oils are preferred. Mineral oils vary widely as totheir crude source, for example, as to whether they are paraffinic,naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal orshale are also useful. Natural oils vary also as to the method used fortheir production and purification, for example, their distillation rangeand whether they are straight run or cracked, hydrorefined, or solventextracted.

Group II and/or Group III hydroprocessed or hydrocracked base stocks,including synthetic oils such as alkyl aromatics and synthetic estersare also well known base stock oils.

Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oilssuch as polymerized and interpolymerized olefins (polybutylenes,polypropylenes, propylene isobutylene copolymers, ethylene-olefincopolymers, and ethylene-alphaolefin copolymers, for example).Polyalphaolefin (PAO) oil base stocks are commonly used synthetichydrocarbon oil. By way of example, PAOs derived from C₈, C₁₀, C₁₂, C₁₄olefins or mixtures thereof may be utilized. See U.S. Pat. Nos.4,956,122; 4,827,064; and 4,827,073.

The number average molecular weights of the PAOs, which are knownmaterials and generally available on a major commercial scale fromsuppliers such as ExxonMobil Chemical Company, Chevron Phillips ChemicalCompany, BP, and others, typically vary from about 250 to about 3,000,although PAO's may be made in viscosities up to about 150 cSt (100° C.).The PAOs are typically comprised of relatively low molecular weighthydrogenated polymers or oligomers of alphaolefins which include, butare not limited to, C₂ to about C₃₂ alphaolefins with the C₈ to aboutC₁₆ alphaolefins, such as 1-octene, 1-decene, 1-dodecene and the like,being preferred. The preferred polyalphaolefins are poly-1-octene,poly-1-decene and poly-1-dodecene and mixtures thereof and mixedolefin-derived polyolefins. However, the dimers of higher olefins in therange of C₁₄ to C₁₈ may be used to provide low viscosity base stocks ofacceptably low volatility.

Depending on the viscosity grade and the starting oligomer, the PAOs maybe predominantly trimers and tetramers of the starting olefins, withminor amounts of the higher oligomers, having a viscosity range of 1.5to 12 cSt. PAO fluids of particular use may include 3.0 cSt, 3.4 cSt,and/or 3.6 cSt and combinations thereof. Mixtures of PAO fluids having aviscosity range of 1.5 to approximately 150 cSt or more may be used ifdesired.

The PAO fluids may be conveniently made by the polymerization of analphaolefin in the presence of a polymerization catalyst such as theFriedel-Crafts catalysts including, for example, aluminum trichloride,boron trifluoride or complexes of boron trifluoride with water, alcoholssuch as ethanol, propanol or butanol, carboxylic acids or esters such asethyl acetate or ethyl propionate. For example the methods disclosed byU.S. Pat. Nos. 4,149,178 or 3,382,291 may be conveniently used herein.Other descriptions of PAO synthesis are found in the following U.S. Pat.Nos. 3,742,082; 3,769,363; 3,876,720; 4,239,930; 4,367,352; 4,413,156;4,434,408; 4,910,355; 4,956,122; and 5,068,487. The dimers of the C₁₄ toC₁₈ olefins are described in U.S. Pat. No. 4,218,330.

Other useful lubricant oil base stocks include wax isomerate base stocksand base oils, comprising hydroisomerized waxy stocks (e.g. waxy stockssuch as gas oils, slack waxes, fuels hydrocracker bottoms, etc.),hydroisomerized Fischer-Tropsch waxes, Gas-to-Liquids (GTL) base stocksand base oils, and other wax isomerate hydroisomerized base stocks andbase oils, or mixtures thereof. Fischer-Tropsch waxes, the high boilingpoint residues of Fischer-Tropsch synthesis, are highly paraffinichydrocarbons with very low sulfur content. The hydroprocessing used forthe production of such base stocks may use an amorphoushydrocracking/hydroisomerization catalyst, such as one of thespecialized lube hydrocracking (LHDC) catalysts or a crystallinehydrocracking/hydroisomerization catalyst, preferably a zeoliticcatalyst. For example, one useful catalyst is ZSM-48 as described inU.S. Pat. No. 5,075,269, the disclosure of which is incorporated hereinby reference in its entirety. Processes for makinghydrocracked/hydroisomerized distillates andhydrocracked/hydroisomerized waxes are described, for example, in U.S.Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as well as inBritish Patent Nos. 1,429,494; 1,350,257; 1,440,230 and 1,390,359. Eachof the aforementioned patents is incorporated herein in their entirety.Particularly favorable processes are described in European PatentApplication Nos. 464546 and 464547, also incorporated herein byreference. Processes using Fischer-Tropsch wax feeds are described inU.S. Pat. Nos. 4,594,172 and 4,943,672, the disclosures of which areincorporated herein by reference in their entirety.

Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized (wax isomerate) base oils beadvantageously used in the instant disclosure, and may have usefulkinematic viscosities at 100° C. of about 3 cSt to about 50 cSt,preferably about 3 cSt to about 30 cSt, more preferably about 3.5 cSt toabout 25 cSt, as exemplified by GTL 4 with kinematic viscosity of about4.0 cSt at 100° C. and a viscosity index of about 141. TheseGas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized base oils may have useful pourpoints of about −20° C. or lower, and under some conditions may haveadvantageous pour points of about −25° C. or lower, with useful pourpoints of about −30° C. to about −40° C. or lower. Useful compositionsof Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived baseoils, and wax-derived hydroisomerized base oils are recited in U.S. Pat.Nos. 6,080,301; 6,090,989, and 6,165,949 for example, and areincorporated herein in their entirety by reference.

The hydrocarbyl aromatics can be used as a base oil or base oilcomponent and can be any hydrocarbyl molecule that contains at leastabout 5% of its weight derived from an aromatic moiety such as abenzenoid moiety or naphthenoid moiety, or their derivatives. Thesehydrocarbyl aromatics include alkyl benzenes, alkyl naphthalenes, alkyldiphenyl oxides, alkyl naphthols, alkyl diphenyl sulfides, alkylatedbis-phenol A, alkylated thiodiphenol, and the like. The aromatic can bemono-alkylated, dialkylated, polyalkylated, and the like. The aromaticcan be mono- or poly-functionalized. The hydrocarbyl groups can also becomprised of mixtures of alkyl groups, alkenyl groups, alkynyl,cycloalkyl groups, cycloalkenyl groups and other related hydrocarbylgroups. The hydrocarbyl groups can range from about C₆ up to about C₆₀with a range of about C₈ to about C₂₀ often being preferred. A mixtureof hydrocarbyl groups is often preferred, and up to about three suchsubstituents may be present. The hydrocarbyl group can optionallycontain sulfur, oxygen, and/or nitrogen containing substituents. Thearomatic group can also be derived from natural (petroleum) sources,provided at least about 5% of the molecule is comprised of an above-typearomatic moiety. Viscosities at 100° C. of approximately 3 cSt to about50 cSt are preferred, with viscosities of approximately 3.4 cSt to about20 cSt often being more preferred for the hydrocarbyl aromaticcomponent. In one embodiment, an alkyl naphthalene where the alkyl groupis primarily comprised of 1-hexadecene is used. Other alkylates ofaromatics can be advantageously used. Naphthalene or methyl naphthalene,for example, can be alkylated with olefins such as octene, decene,dodecene, tetradecene or higher, mixtures of similar olefins, and thelike. Useful concentrations of hydrocarbyl aromatic in a lubricant oilcomposition can be about 2% to about 25%, preferably about 4% to about20%, and more preferably about 4% to about 15%, depending on theapplication.

Alkylated aromatics such as the hydrocarbyl aromatics of the presentdisclosure may be produced by well-known Friedel-Crafts alkylation ofaromatic compounds. See Friedel-Crafts and Related Reactions, Olah, G.A. (ed.), Inter-science Publishers, New York, 1963. For example, anaromatic compound, such as benzene or naphthalene, is alkylated by anolefin, alkyl halide or alcohol in the presence of a Friedel-Craftscatalyst. See Friedel-Crafts and Related Reactions, Vol. 2, part 1,chapters 14, 17, and 18, See Olah, G. A. (ed.), Inter-sciencePublishers, New York, 1964. Many homogeneous or heterogeneous, solidcatalysts are known to one skilled in the art. The choice of catalystdepends on the reactivity of the starting materials and product qualityrequirements. For example, strong acids such as AlCl₃, BF₃, or HF may beused. In some cases, milder catalysts such as FeCl₃ or SnCl₄ arepreferred. Newer alkylation technology uses zeolites or solid superacids.

Esters comprise a useful base stock. Additive solvency and sealcompatibility characteristics may be secured by the use of esters suchas the esters of dibasic acids with monoalkanols and the polyol estersof monocarboxylic acids. Esters of the former type include, for example,the esters of dicarboxylic acids such as phthalic acid, succinic acid,alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid,suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic aciddimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc.,with a variety of alcohols such as butyl alcohol, hexyl alcohol, dodecylalcohol, 2-ethylhexyl alcohol, etc. Specific examples of these types ofesters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexylfumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, etc.

Particularly useful synthetic esters are those which are obtained byreacting one or more polyhydric alcohols, preferably the hinderedpolyols (such as the neopentyl polyols, e.g., neopentyl glycol,trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylolpropane, pentaerythritol and dipentaerythritol) with alkanoic acidscontaining at least about 4 carbon atoms, preferably C₅ to C₃₀ acidssuch as saturated straight chain fatty acids including caprylic acid,capric acid, lauric acid, myristic acid, palmitic acid, stearic acid,arachic acid, and behenic acid, or the corresponding branched chainfatty acids or unsaturated fatty acids such as oleic acid, or mixturesof any of these materials.

Suitable synthetic ester components include the esters of trimethylolpropane, trimethylol butane, trimethylol ethane, pentaerythritol and/ordipentaerythritol with one or more monocarboxylic acids containing fromabout 5 to about 10 carbon atoms. These esters are widely availablecommercially, for example, the Mobil P-41 and P-51 esters of ExxonMobilChemical Company.

Also useful are esters derived from renewable material such as coconut,palm, rapeseed, soy, sunflower and the like. These esters may bemonoesters, di-esters, polyol esters, complex esters, or mixturesthereof. These esters are widely available commercially, for example,the Esterex NP 343 ester of ExxonMobil Chemical Company.

Engine oil formulations containing renewable esters are included in thisdisclosure. For such formulations, the renewable content of the ester istypically greater than about 70 weight percent, preferably more thanabout 80 weight percent and most preferably more than about 90 weightpercent.

Other useful fluids of lubricating viscosity include non-conventional orunconventional base stocks that have been processed, preferablycatalytically, or synthesized to provide high performance lubricationcharacteristics.

Non-conventional or unconventional base stocks/base oils include one ormore of a mixture of base stock(s) derived from one or moreGas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate basestock(s) derived from natural wax or waxy feeds, mineral and ornon-mineral oil waxy feed stocks such as slack waxes, natural waxes, andwaxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxyraffinate, hydrocrackate, thermal crackates, or other mineral, mineraloil, or even non-petroleum oil derived waxy materials such as waxymaterials received from coal liquefaction or shale oil, and mixtures ofsuch base stocks.

GTL materials are materials that are derived via one or more synthesis,combination, transformation, rearrangement, and/ordegradation/deconstructive processes from gaseous carbon-containingcompounds, hydrogen-containing compounds and/or elements as feed stockssuch as hydrogen, carbon dioxide, carbon monoxide, water, methane,ethane, ethylene, acetylene, propane, propylene, propyne, butane,butylenes, and butynes. GTL base stocks and/or base oils are GTLmaterials of lubricating viscosity that are generally derived fromhydrocarbons; for example, waxy synthesized hydrocarbons, that arethemselves derived from simpler gaseous carbon-containing compounds,hydrogen-containing compounds and/or elements as feed stocks. GTL basestock(s) and/or base oil(s) include oils boiling in the lube oil boilingrange (1) separated/fractionated from synthesized GTL materials such as,for example, by distillation and subsequently subjected to a final waxprocessing step which involves either or both of a catalytic dewaxingprocess, or a solvent dewaxing process, to produce lube oils ofreduced/low pour point; (2) synthesized wax isomerates, comprising, forexample, hydrodewaxed or hydroisomerized cat and/or solvent dewaxedsynthesized wax or waxy hydrocarbons; (3) hydrodewaxed orhydroisomerized cat and/or solvent dewaxed Fischer-Tropsch (F-T)material (i.e., hydrocarbons, waxy hydrocarbons, waxes and possibleanalogous oxygenates); preferably hydrodewaxed orhydroisomerized/followed by cat and/or solvent dewaxing dewaxed F-T waxyhydrocarbons, or hydrodewaxed or hydroisomerized/followed by cat (orsolvent) dewaxing dewaxed, F-T waxes, or mixtures thereof.

GTL base stock(s) and/or base oil(s) derived from GTL materials,especially, hydrodewaxed or hydroisomerized/followed by cat and/orsolvent dewaxed wax or waxy feed, preferably F-T material derived basestock(s) and/or base oil(s), are characterized typically as havingkinematic viscosities at 100° C. of from about 2 mm²/s to about 50 mm²/s(ASTM D445). They are further characterized typically as having pourpoints of −5° C. to about −40° C. or lower

(ASTM D97). They are also characterized typically as having viscosityindices of about 80 to about 140 or greater (ASTM D2270).

In addition, the GTL base stock(s) and/or base oil(s) are typicallyhighly paraffinic (>90% saturates), and may contain mixtures ofmonocycloparaffins and multicycloparaffins in combination withnon-cyclic isoparaffins. The ratio of the naphthenic (i.e.,cycloparaffin) content in such combinations varies with the catalyst andtemperature used. Further, GTL base stock(s) and/or base oil(s)typically have very low sulfur and nitrogen content, generallycontaining less than about 10 ppm, and more typically less than about 5ppm of each of these elements. The sulfur and nitrogen content of GTLbase stock(s) and/or base oil(s) obtained from F-T material, especiallyF-T wax, is essentially nil. In addition, the absence of phosphorus andaromatics make this materially especially suitable for the formulationof low SAP products.

The term GTL base stock and/or base oil and/or wax isomerate base stockand/or base oil is to be understood as embracing individual fractions ofsuch materials of wide viscosity range as recovered in the productionprocess, mixtures of two or more of such fractions, as well as mixturesof one or two or more low viscosity fractions with one, two or morehigher viscosity fractions to produce a blend wherein the blend exhibitsa target kinematic viscosity.

The GTL material, from which the GTL base stock(s) and/or base oil(s)is/are derived is preferably an F-T material (i.e., hydrocarbons, waxyhydrocarbons, wax).

Base oils for use in the formulated lubricating oils useful in thepresent disclosure are any of the variety of oils corresponding to APIGroup I, Group II, Group III, Group IV, and Group V oils and mixturesthereof, preferably API Group II, Group III, Group IV, and Group V oilsand mixtures thereof, more preferably the Group III to Group V base oilsdue to their exceptional volatility, stability, viscometric andcleanliness features. Minor quantities of Group I stock, such as theamount used to dilute additives for blending into formulated lube oilproducts, can be tolerated but should be kept to a minimum, i.e. amountsonly associated with their use as diluent/carrier oil for additives usedon an “as-received” basis. Even in regard to the Group II stocks, it ispreferred that the Group II stock be in the higher quality rangeassociated with that stock, i.e. a Group II stock having a viscosityindex in the range 100<VI<120.

The base oil constitutes the major component of the engine oil lubricantcomposition of the present disclosure and typically is present in anamount ranging from about 50 to about 99 weight percent, preferably fromabout 70 to about 95 weight percent, and more preferably from about 85to about 95 weight percent, based on the total weight of thecomposition. The base oil may be selected from any of the synthetic ornatural oils typically used as crankcase lubricating oils forspark-ignited and compression-ignited engines. The base oil convenientlyhas a kinematic viscosity, according to ASTM standards, of about 2.5 cStto about 12 cSt (or mm²/s) at 100° C. and preferably of about 2.5 cSt toabout 9 cSt (or mm²/s) at 100° C. Mixtures of synthetic and natural baseoils may be used if desired. Bi-modal mixtures of Group I, II, III, IV,and/or V base stocks may be used if desired.

Functionalized Quercetin Antioxidants

The antioxidants of this disclosure are functionalized quercetins.Quercetin has the following structural formula:

Functionalized quercetin derivatives have the following generalstructural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

A preferred functionalized quercetin antioxidant is partially esterifiedquercetin or a partially etherified quercetin.

In an embodiment, the functionalized quercetin antioxidant is thereaction product of quercetin with a carboxylic acid. In particular, thefunctionalized quercetin antioxidant is the reaction product ofquercetin with a carboxylic acid, in which the molar ratio of quercetin:acid is about 1:1 to about 1:4, preferably the molar ratio ofquercetin:acid is about 1:1 to about 1:3, and more preferably the molarratio of quercetin:acid is about 1:2 to about 1:3.

In an embodiment, the functionalized quercetin antioxidant is thereaction product of quercetin with 2-hexyldecanoic acid, in which themolar ratio of quercetin:2-hexyldecanoic acid is about 1:1 to about 1:4,preferably the molar ratio of quercetin:2-hexyldecanoic acid is about1:1 to about 1:3, and more preferably the molar ratio ofquercetin:2-hexyldecanoic acid is about 1:2 to about 1:3.

In another embodiment, the functionalized quercetin antioxidant is thereaction product of quercetin with an alkylthiopropionic acid. Inparticular, the functionalized quercetin antioxidant is the reactionproduct of quercetin with alkylthiopropionic acid, in which the molarratio of quercetin: alkylthiopropionic acid is about 1:1 to about 1:4,preferably the molar ratio of quercetin: alkylthiopropionic acid isabout 1:1 to about 1:3, and more preferably the molar ratio ofquercetin: alkylthiopropionic acid is about 1:2 to about 1:4.

Yet in another embodiment, the functionalized quercetin antioxidant isthe reaction product of quercetin with an mPAOthiopropionic acid. Inparticular, the functionalized quercetin antioxidant is the reactionproduct of quercetin with mPAOthiopropionic acid, in which the molarratio of quercetin:mPAOthiopropionic acid is about 1:1 to about 1:4,preferably the molar ratio of quercetin:mPAOthiopropionic acid is about1:1 to about 1:3, and more preferably the molar ratio ofquercetin:mPAOthiopropionic acid is about 1:1 to about 1:2.

In a further embodiment, the functionalized quercetin antioxidant is thereaction product of quercetin with alkyl bromide to form an ether. Inparticular, the functionalized quercetin antioxidant is the reactionproduct of quercetin with an alkyl bromide, in which the molar ratio ofquercetin:alkyl bromide is about 1:1 to about 1:4, preferably the molarratio of quercetin:alkyl bromide is about 1:1 to about 1:3, and morepreferably the molar ratio of quercetin: alkyl bromide is about 1:2 toabout 1:3.

In a further embodiment, the functionalized quercetin antioxidant is thereaction product of quercetin with a brominated atactic polypropylene(aPP) to form an ether. In particular, the functionalized quercetinantioxidant is the reaction product of quercetin with a brominatedatactic polypropylene (aPP), in which the molar ratio of quercetin:aPPis about 1:1 to about 1:4, preferably the molar ratio of quercetin: aPPis about 1:1 to about 1:3, and more preferably the molar ratio ofquercetin:aPP is about 1:1 to about 1:2.

Reaction conditions for the esterification of quercetin, in particularthe reaction of quercetin with a carboxylic acid, such as temperature,pressure and contact time, may vary greatly and any suitable combinationof such conditions may be employed herein. The reaction temperature maybe between about 10° C. to about 150° C., and most preferably betweenabout 20° C. to about 80° C. Normally the reaction is carried out underambient pressure and the contact time may vary from a matter of secondsor minutes to a few hours or greater. The reactants can be added to thereaction mixture or combined in any order. The stir time employed canrange from about 0.1 to about 400 hours, preferably from about 1 to 75hours, and more preferably from about 4 to 16 hours.

Reaction conditions for the etherification of quercetin, such astemperature, pressure and contact time, may vary greatly and anysuitable combination of such conditions may be employed herein. Thereaction temperature may be between about 10° C. to about 150° C., andmost preferably between about 20° C. to about 80° C. Normally thereaction is carried out under ambient pressure and the contact time mayvary from a matter of seconds or minutes to a few hours or greater. Thereactants can be added to the reaction mixture or combined in any order.The stir time employed can range from about 0.1 to about 400 hours,preferably from about 1 to 75 hours, and more preferably from about 4 to16 hours.

Illustrative functionalized quercetin antioxidants include, for example,those having the structural formula:

The at least one functionalized quercetin antioxidant is present in anamount from about 0.01 to 5 weight percent, or from about 0.01 to 4.5weight percent, or from about 0.01 to 4 weight percent, or from about0.01 to 3.5 weight percent, or from about 0.01 to 3 weight percent, orfrom about 0.01 to 2.5 weight percent, or from about 0.01 to 2 weightpercent, or from about 0.01 to 1.5 weight percent, or from about 0.01 to1 weight percent, based on the total weight of the lubricating oil.

In comparison with quercetin antioxidant, the functionalized quercetinantioxidants of this disclosure exhibit improved solubility inlubricating oils, and enhanced activity as an antioxidant.

In an embodiment, the functionalized quercetin antioxidants of thisdisclosure exhibit equivalent or better performance than commerciallyavailable amine phenolic antioxidants. The functionalized quercetinantioxidants of this disclosure exhibit equivalent or better performanceat lower treat rates, than commercially available amine phenolicantioxidants. The functionalized quercetin antioxidants of thisdisclosure are particularly effective when used in conjunction withaminic antioxidants as shown in FIG. 1.

In an embodiment, in an engine or other mechanical component lubricatedwith the lubricating oil, antioxidant performance is improved ascompared to antioxidant performance achieved using a lubricating oilcontaining a phenolic or aminic antioxidant, as determined by theLubricant Oxidation Test as described herein or Catalytic Oxidation Testas described herein.

As used herein, “functionalized” means any chemical group formed byreaction with quercetin that changes the structural chemistry ofquercetin (e.g., esters, ethers, and the like) and also the propertiesof quercetin (e.g., solubility, antioxidant properties, and the like).Illustrative chemical groups include, for example, esters, ethers, andthe like. Functionalized reactions include, for example, esterification,etherification, and the like.

Other Lubricating Oil Additives

The formulated lubricating oil useful in the present disclosure mayadditionally contain one or more of the other commonly used lubricatingoil performance additives including but not limited to antiwearadditives, dispersants, detergents, viscosity modifiers, corrosioninhibitors, rust inhibitors, metal deactivators, extreme pressureadditives, anti-seizure agents, other antioxidants, wax modifiers,viscosity modifiers, fluid-loss additives, seal compatibility agents,lubricity agents, friction modifiers, antifoam agents, anti-stainingagents, chromophoric agents, defoamants, demulsifiers, emulsifiers,densifiers, wetting agents, gelling agents, tackiness agents, colorants,and others. For a review of many commonly used additives, see Klamann inLubricants and Related Products, Verlag Chemie, Deerfield Beach, Fla.;ISBN 0-89573-177-0. Reference is also made to “Lubricant Additives” byM. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J.(1973); see also U.S. Pat. No. 7,704,930, the disclosure of which isincorporated herein in its entirety. These additives are commonlydelivered with varying amounts of diluent oil, that may range from 5weight percent to 50 weight percent.

The additives useful in this disclosure do not have to be soluble in thelubricating oils. Insoluble additives in oil can be dispersed in thelubricating oils of this disclosure.

The types and quantities of performance additives used in combinationwith the instant disclosure in lubricant compositions are not limited bythe examples shown herein as illustrations.

Antiwear Additives

A metal alkylthiophosphate and more particularly a metal dialkyl dithiophosphate in which the metal constituent is zinc, or zinc dialkyl dithiophosphate (ZDDP) can be a useful component of the lubricating oils ofthis disclosure. ZDDP can be derived from primary alcohols, secondaryalcohols or mixtures thereof. ZDDP compounds generally are of theformula

Zn[SP(S)(OR¹)(OR²)]₂

where R¹ and R² are C₁-C₁₈ alkyl groups, preferably C₂-C₁₂ alkyl groups.These alkyl groups may be straight chain or branched. Alcohols used inthe ZDDP can be 2-propanol, butanol, secondary butanol, pentanols,hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethylhexanol, alkylated phenols, and the like. Mixtures of secondary alcoholsor of primary and secondary alcohol can be preferred. Alkyl aryl groupsmay also be used.

Preferable zinc dithiophosphates which are commercially availableinclude secondary zinc dithiophosphates such as those available from forexample, The Lubrizol Corporation under the trade designations “LZ677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite underthe trade designation “OLOA 262” and from for example Afton Chemicalunder the trade designation “HITEC 7169”.

The ZDDP is typically used in amounts of from about 0.4 weight percentto about 1.2 weight percent, preferably from about 0.5 weight percent toabout 1.0 weight percent, and more preferably from about 0.6 weightpercent to about 0.8 weight percent, based on the total weight of thelubricating oil, although more or less can often be used advantageously.Preferably, the ZDDP is a secondary ZDDP and present in an amount offrom about 0.6 to 1.0 weight percent of the total weight of thelubricating oil.

Low phosphorus engine oil formulations are included in this disclosure.For such formulations, the phosphorus content is typically less thanabout 0.12 weight percent preferably less than about 0.10 weight percentand most preferably less than about 0.085 weight percent.

Dispersants

During engine operation, oil-insoluble oxidation byproducts areproduced. Dispersants help keep these byproducts in solution, thusdiminishing their deposition on metal surfaces. Dispersants used in theformulation of the lubricating oil may be ashless or ash-forming innature. Preferably, the dispersant is ashless. So called ashlessdispersants are organic materials that form substantially no ash uponcombustion. For example, non-metal-containing or borated metal-freedispersants are considered ashless. In contrast, metal-containingdetergents discussed herein form ash upon combustion.

Suitable dispersants typically contain a polar group attached to arelatively high molecular weight hydrocarbon chain. The polar grouptypically contains at least one element of nitrogen, oxygen, orphosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

A particularly useful class of dispersants are the (poly)alkenylsuccinicderivatives, typically produced by the reaction of a long chainhydrocarbyl substituted succinic compound, usually a hydrocarbylsubstituted succinic anhydride, with a polyhydroxy or polyaminocompound. The long chain hydrocarbyl group constituting the oleophilicportion of the molecule which confers solubility in the oil, is normallya polyisobutylene group. Many examples of this type of dispersant arewell known commercially and in the literature. Exemplary U.S. patentsdescribing such dispersants are U.S. Pat. Nos. 3,172,892; 3,2145,707;3,219,666; 3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012;3,630,904; 3,632,511; 3,787,374 and 4,234,435. Other types of dispersantare described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025;3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574;3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250;3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. Afurther description of dispersants may be found, for example, inEuropean Patent Application No. 471 071, to which reference is made forthis purpose.

Hydrocarbyl-substituted succinic acid and hydrocarbyl-substitutedsuccinic anhydride derivatives are useful dispersants. In particular,succinimide, succinate esters, or succinate ester amides prepared by thereaction of a hydrocarbon-substituted succinic acid compound preferablyhaving at least 50 carbon atoms in the hydrocarbon substituent, with atleast one equivalent of an alkylene amine are particularly useful.

Succinimides are formed by the condensation reaction between hydrocarbylsubstituted succinic anhydrides and amines. Molar ratios can varydepending on the polyamine. For example, the molar ratio of hydrocarbylsubstituted succinic anhydride to TEPA can vary from about 1:1 to about5:1. Representative examples are shown in U.S. Pat. Nos. 3,087,936;3,172,892; 3,219,666; 3,272,746; 3,322,670; and 3,652,616, 3,948,800;and Canada Patent No. 1,094,044.

Succinate esters are formed by the condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alcohols or polyols.Molar ratios can vary depending on the alcohol or polyol used. Forexample, the condensation product of a hydrocarbyl substituted succinicanhydride and pentaerythritol is a useful dispersant.

Succinate ester amides are formed by condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alkanol amines. Forexample, suitable alkanol amines include ethoxylatedpolyalkylpolyamines, propoxylated polyalkylpolyamines andpolyalkenylpolyamines such as polyethylene polyamines. One example ispropoxylated hexamethylenediamine. Representative examples are shown inU.S. Pat. No. 4,426,305.

The molecular weight of the hydrocarbyl substituted succinic anhydridesused in the preceding paragraphs will typically range between 800 and2,500 or more. The above products can be post-reacted with variousreagents such as sulfur, oxygen, formaldehyde, carboxylic acids such asoleic acid. The above products can also be post reacted with boroncompounds such as boric acid, borate esters or highly borateddispersants, to form borated dispersants generally having from about 0.1to about 5 moles of boron per mole of dispersant reaction product.

Mannich base dispersants are made from the reaction of alkylphenols,formaldehyde, and amines. See U.S. Pat. No. 4,767,551, which isincorporated herein by reference. Process aids and catalysts, such asoleic acid and sulfonic acids, can also be part of the reaction mixture.Molecular weights of the alkylphenols range from 800 to 2,500.Representative examples are shown in U.S. Pat. Nos. 3,697,574;3,703,536; 3,704,308; 3,751,365; 3,756,953; 3,798,165; and 3,803,039.

Typical high molecular weight aliphatic acid modified Mannichcondensation products useful in this disclosure can be prepared fromhigh molecular weight alkyl-substituted hydroxyaromatics or HNR₂group-containing reactants.

Hydrocarbyl substituted amine ashless dispersant additives are wellknown to one skilled in the art; see, for example, U.S. Pat. Nos.3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209, and 5,084,197.

Preferred dispersants include borated and non-borated succinimides,including those derivatives from mono-succinimides, bis-succinimides,and/or mixtures of mono- and bis-succinimides, wherein the hydrocarbylsuccinimide is derived from a hydrocarbylene group such aspolyisobutylene having a Mn of from about 500 to about 5000, or fromabout 1000 to about 3000, or about 1000 to about 2000, or a mixture ofsuch hydrocarbylene groups, often with high terminal vinylic groups.Other preferred dispersants include succinic acid-esters and amides,alkylphenol-polyamine-coupled Mannich adducts, their capped derivatives,and other related components.

Polymethacrylate or polyacrylate derivatives are another class ofdispersants. These dispersants are typically prepared by reacting anitrogen containing monomer and a methacrylic or acrylic acid esterscontaining 5-25 carbon atoms in the ester group. Representative examplesare shown in U.S. Pat. Nos. 2, 100, 993, and 6,323,164. Polymethacrylateand polyacrylate dispersants are normally used as multifunctionalviscosity modifiers. The lower molecular weight versions can be used aslubricant dispersants or fuel detergents.

Illustrative preferred dispersants useful in this disclosure includethose derived from polyalkenyl-substituted mono- or dicarboxylic acid,anhydride or ester, which dispersant has a polyalkenyl moiety with anumber average molecular weight of at least 900 and from greater than1.3 to 1.7, preferably from greater than 1.3 to 1.6, most preferablyfrom greater than 1.3 to 1.5, functional groups (mono- or dicarboxylicacid producing moieties) per polyalkenyl moiety (a medium functionalitydispersant). Functionality (F) can be determined according to thefollowing formula:

F=(SAP×M _(n))/((112,200×A.I.)−(SAP×98))

wherein SAP is the saponification number (i.e., the number of milligramsof KOH consumed in the complete neutralization of the acid groups in onegram of the succinic-containing reaction product, as determinedaccording to ASTM D94); M_(n) is the number average molecular weight ofthe starting olefin polymer; and A.I. is the percent active ingredientof the succinic-containing reaction product (the remainder beingunreacted olefin polymer, succinic anhydride and diluent).

The polyalkenyl moiety of the dispersant may have a number averagemolecular weight of at least 900, suitably at least 1500, preferablybetween 1800 and 3000, such as between 2000 and 2800, more preferablyfrom about 2100 to 2500, and most preferably from about 2200 to about2400. The molecular weight of a dispersant is generally expressed interms of the molecular weight of the polyalkenyl moiety. This is becausethe precise molecular weight range of the dispersant depends on numerousparameters including the type of polymer used to derive the dispersant,the number of functional groups, and the type of nucleophilic groupemployed.

Polymer molecular weight, specifically M_(n), can be determined byvarious known techniques. One convenient method is gel permeationchromatography (GPC), which additionally provides molecular weightdistribution information (see W. W. Yau, J. J. Kirkland and D. D. Bly,“Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, NewYork, 1979). Another useful method for determining molecular weight,particularly for lower molecular weight polymers, is vapor pressureosmometry (e.g., ASTM D3592).

The polyalkenyl moiety in a dispersant preferably has a narrow molecularweight distribution (MWD), also referred to as polydispersity, asdetermined by the ratio of weight average molecular weight (M_(w)) tonumber average molecular weight (M_(n)). Polymers having a M_(w)/M_(n)of less than 2.2, preferably less than 2.0, are most desirable. Suitablepolymers have a polydispersity of from about 1.5 to 2.1, preferably fromabout 1.6 to about 1.8.

Suitable polyalkenes employed in the formation of the dispersantsinclude homopolymers, interpolymers or lower molecular weighthydrocarbons. One family of such polymers comprise polymers of ethyleneand/or at least one C₃ to C₂ alpha-olefin having the formula H₂C═CHR¹wherein R¹ is a straight or branched chain alkyl radical comprising 1 to26 carbon atoms and wherein the polymer contains carbon-to-carbonunsaturation, and a high degree of terminal ethenylidene unsaturation.Preferably, such polymers comprise interpolymers of ethylene and atleast one alpha-olefin of the above formula, wherein R¹ is alkyl of from1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8 carbonatoms, and more preferably still of from 1 to 2 carbon atoms.

Another useful class of polymers is polymers prepared by cationicpolymerization of monomers such as isobutene and styrene. Commonpolymers from this class include polyisobutenes obtained bypolymerization of a C₄ refinery stream having a butene content of 35 to75% by wt., and an isobutene content of 30 to 60% by wt. A preferredsource of monomer for making poly-n-butenes is petroleum feedstreamssuch as Raffinate II. These feedstocks are disclosed in the art such asin U.S. Pat. No. 4,952,739. A preferred embodiment utilizespolyisobutylene prepared from a pure isobutylene stream or a Raffinate Istream to prepare reactive isobutylene polymers with terminal vinylideneolefins. Polyisobutene polymers that may be employed are generally basedon a polymer chain of from 1500 to 3000.

The dispersant(s) are preferably non-polymeric (e.g., mono- orbis-succinimides). Such dispersants can be prepared by conventionalprocesses such as disclosed in U.S. Patent Application Publication No.2008/0020950, the disclosure of which is incorporated herein byreference.

The dispersant(s) can be borated by conventional means, as generallydisclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and 5,430,105.

Such dispersants may be used in an amount of about 0.01 to 20 weightpercent or 0.01 to 10 weight percent, preferably about 0.5 to 8 weightpercent, or more preferably 0.5 to 4 weight percent. Or such dispersantsmay be used in an amount of about 2 to 12 weight percent, preferablyabout 4 to 10 weight percent, or more preferably 6 to 9 weight percent.On an active ingredient basis, such additives may be used in an amountof about 0.06 to 14 weight percent, preferably about 0.3 to 6 weightpercent. The hydrocarbon portion of the dispersant atoms can range fromC₆₀ to C₁₀₀₀, or from C₇₀ to C₃₀₀, or from C₇₀ to C₂₀₀. Thesedispersants may contain both neutral and basic nitrogen, and mixtures ofboth. Dispersants can be end-capped by borates and/or cyclic carbonates.Nitrogen content in the finished oil can vary from about 200 ppm byweight to about 2000 ppm by weight, preferably from about 200 ppm byweight to about 1200 ppm by weight. Basic nitrogen can vary from about100 ppm by weight to about 1000 ppm by weight, preferably from about 100ppm by weight to about 600 ppm by weight.

As used herein, the dispersant concentrations are given on an “asdelivered” basis. Typically, the active dispersant is delivered with aprocess oil. The “as delivered” dispersant typically contains from about20 weight percent to about 80 weight percent, or from about 40 weightpercent to about 60 weight percent, of active dispersant in the “asdelivered” dispersant product.

Detergents

Illustrative detergents useful in this disclosure include, for example,alkali metal detergents, alkaline earth metal detergents, or mixtures ofone or more alkali metal detergents and one or more alkaline earth metaldetergents. A typical detergent is an anionic material that contains along chain hydrophobic portion of the molecule and a smaller anionic oroleophobic hydrophilic portion of the molecule. The anionic portion ofthe detergent is typically derived from an organic acid such as asulfur-containing acid, carboxylic acid (e.g., salicylic acid),phosphorus-containing acid, phenol, or mixtures thereof. The counterionis typically an alkaline earth or alkali metal. The detergent can beoverbased as described herein.

The detergent is preferably a metal salt of an organic or inorganicacid, a metal salt of a phenol, or mixtures thereof. The metal ispreferably selected from an alkali metal, an alkaline earth metal, andmixtures thereof. The organic or inorganic acid is selected from analiphatic organic or inorganic acid, a cycloaliphatic organic orinorganic acid, an aromatic organic or inorganic acid, and mixturesthereof.

The metal is preferably selected from an alkali metal, an alkaline earthmetal, and mixtures thereof. More preferably, the metal is selected fromcalcium (Ca), magnesium (Mg), and mixtures thereof.

The organic acid or inorganic acid is preferably selected from asulfur-containing acid, a carboxylic acid, a phosphorus-containing acid,and mixtures thereof.

Preferably, the metal salt of an organic or inorganic acid or the metalsalt of a phenol comprises calcium phenate, calcium sulfonate, calciumsalicylate, magnesium phenate, magnesium sulfonate, magnesiumsalicylate, an overbased detergent, and mixtures thereof.

Salts that contain a substantially stochiometric amount of the metal aredescribed as neutral salts and have a total base number (TBN, asmeasured by ASTM D2896) of from 0 to 80. Many compositions areoverbased, containing large amounts of a metal base that is achieved byreacting an excess of a metal compound (a metal hydroxide or oxide, forexample) with an acidic gas (such as carbon dioxide). Useful detergentscan be neutral, mildly overbased, or highly overbased. These detergentscan be used in mixtures of neutral, overbased, highly overbased calciumsalicylate, sulfonates, phenates and/or magnesium salicylate,sulfonates, phenates. The TBN ranges can vary from low, medium to highTBN products, including as low as 0 to as high as 600. Preferably theTBN delivered by the detergent is between 1 and 20. More preferablybetween 1 and 12. Mixtures of low, medium, high TBN can be used, alongwith mixtures of calcium and magnesium metal based detergents, andincluding sulfonates, phenates, salicylates, and carboxylates. Adetergent mixture with a metal ratio of 1, in conjunction of a detergentwith a metal ratio of 2, and as high as a detergent with a metal ratioof 5, can be used. Borated detergents can also be used.

Alkaline earth phenates are another useful class of detergent. Thesedetergents can be made by reacting alkaline earth metal hydroxide oroxide (CaO, Ca(OH)₂, BaO, Ba(OH)₂, MgO, Mg(OH)₂, for example) with analkyl phenol or sulfurized alkylphenol. Useful alkyl groups includestraight chain or branched C₁-C₃₀ alkyl groups, preferably, C₄-C₂₀ ormixtures thereof. Examples of suitable phenols include isobutylphenol,2-ethylhexylphenol, nonylphenol, dodecyl phenol, and the like. It shouldbe noted that starting alkylphenols may contain more than one alkylsubstituent that are each independently straight chain or branched andcan be used from 0.5 to 6 weight percent. When a non-sulfurizedalkylphenol is used, the sulfurized product may be obtained by methodswell known in the art. These methods include heating a mixture ofalkylphenol and sulfurizing agent (including elemental sulfur, sulfurhalides such as sulfur dichloride, and the like) and then reacting thesulfurized phenol with an alkaline earth metal base.

In accordance with this disclosure, metal salts of carboxylic acids arepreferred detergents. These carboxylic acid detergents may be preparedby reacting a basic metal compound with at least one carboxylic acid andremoving free water from the reaction product. These compounds may beoverbased to produce the desired TBN level. Detergents made fromsalicylic acid are one preferred class of detergents derived fromcarboxylic acids. Useful salicylates include long chain alkylsalicylates. One useful family of compositions is of the formula

where R is an alkyl group having 1 to about 30 carbon atoms, n is aninteger from 1 to 4, and M is an alkaline earth metal. Preferred Rgroups are alkyl chains of at least C₁₁, preferably C₁₃ or greater. Rmay be optionally substituted with substituents that do not interferewith the detergent's function. M is preferably, calcium, magnesium,barium, or mixtures thereof. More preferably, M is calcium.

Hydrocarbyl-substituted salicylic acids may be prepared from phenols bythe Kolbe reaction (see U.S. Pat. No. 3,595,791). The metal salts of thehydrocarbyl-substituted salicylic acids may be prepared by doubledecomposition of a metal salt in a polar solvent such as water oralcohol.

Alkaline earth metal phosphates are also used as detergents and areknown in the art.

Detergents may be simple detergents or what is known as hybrid orcomplex detergents. The latter detergents can provide the properties oftwo detergents without the need to blend separate materials. See U.S.Pat. No. 6,034,039.

Preferred detergents include calcium sulfonates, magnesium sulfonates,calcium salicylates, magnesium salicylates, calcium phenates, magnesiumphenates, and other related components (including borated detergents),and mixtures thereof. Preferred mixtures of detergents include magnesiumsulfonate and calcium salicylate, magnesium sulfonate and calciumsulfonate, magnesium sulfonate and calcium phenate, calcium phenate andcalcium salicylate, calcium phenate and calcium sulfonate, calciumphenate and magnesium salicylate, calcium phenate and magnesium phenate.Overbased detergents are also preferred.

The detergent concentration in the lubricating oils of this disclosurecan range from about 0.5 to about 6.0 weight percent, preferably about0.6 to 5.0 weight percent, and more preferably from about 0.8 weightpercent to about 4.0 weight percent, based on the total weight of thelubricating oil.

As used herein, the detergent concentrations are given on an “asdelivered” basis. Typically, the active detergent is delivered with aprocess oil. The “as delivered” detergent typically contains from about20 weight percent to about 100 weight percent, or from about 40 weightpercent to about 60 weight percent, of active detergent in the “asdelivered” detergent product.

Viscosity Modifiers

Viscosity modifiers (also known as viscosity index improvers (VIimprovers), and viscosity improvers) can be included in the lubricantcompositions of this disclosure.

Viscosity modifiers provide lubricants with high and low temperatureoperability. These additives impart shear stability at elevatedtemperatures and acceptable viscosity at low temperatures.

Suitable viscosity modifiers include high molecular weight hydrocarbons,polyesters and viscosity modifier dispersants that function as both aviscosity modifier and a dispersant. Typical molecular weights of thesepolymers are between about 10,000 to 1,500,000, more typically about20,000 to 1,200,000, and even more typically between about 50,000 and1,000,000.

Examples of suitable viscosity modifiers are linear or star-shapedpolymers and copolymers of methacrylate, butadiene, olefins, oralkylated styrenes. Polyisobutylene is a commonly used viscositymodifier. Another suitable viscosity modifier is polymethacrylate(copolymers of various chain length alkyl methacrylates, for example),some formulations of which also serve as pour point depressants. Othersuitable viscosity modifiers include copolymers of ethylene andpropylene, hydrogenated block copolymers of styrene and isoprene, andpolyacrylates (copolymers of various chain length acrylates, forexample). Specific examples include styrene-isoprene orstyrene-butadiene based polymers of 50,000 to 200,000 molecular weight.

Olefin copolymers are commercially available from Chevron OroniteCompany LLC under the trade designation “PARATONE®” (such as “PARATONE®8921” and “PARATONE® 8941”); from Afton Chemical Corporation under thetrade designation “HiTEC®” (such as “HiTEC® 5850B”; and from TheLubrizol Corporation under the trade designation “Lubrizol® 7067C”.Hydrogenated polyisoprene star polymers are commercially available fromInfineum International Limited, e.g., under the trade designation“SV200” and “SV600”. Hydrogenated diene-styrene block copolymers arecommercially available from Infineum International Limited, e.g., underthe trade designation “SV 50”.

The polymethacrylate or polyacrylate polymers can be linear polymerswhich are available from Evnoik Industries under the trade designation“Viscoplex®” (e.g., Viscoplex 6-954) or star polymers which areavailable from Lubrizol Corporation under the trade designation Asteric™(e.g., Lubrizol 87708 and Lubrizol 87725).

Illustrative vinyl aromatic-containing polymers useful in thisdisclosure may be derived predominantly from vinyl aromatic hydrocarbonmonomer. Illustrative vinyl aromatic-containing copolymers useful inthis disclosure may be represented by the following general formula:

A−B

wherein A is a polymeric block derived predominantly from vinyl aromatichydrocarbon monomer, and B is a polymeric block derived predominantlyfrom conjugated diene monomer.

In an embodiment of this disclosure, the viscosity modifiers may be usedin an amount of less than about 10 weight percent, preferably less thanabout 7 weight percent, more preferably less than about 4 weightpercent, and in certain instances, may be used at less than 2 weightpercent, preferably less than about 1 weight percent, and morepreferably less than about 0.5 weight percent, based on the total weightof the formulated oil or lubricating engine oil. Viscosity modifiers aretypically added as concentrates, in large amounts of diluent oil.

As used herein, the viscosity modifier concentrations are given on an“as delivered” basis. Typically, the active polymer is delivered with adiluent oil. The “as delivered” viscosity modifier typically containsfrom 20 weight percent to 75 weight percent of an active polymer forpolymethacrylate or polyacrylate polymers, or from 8 weight percent to20 weight percent of an active polymer for olefin copolymers,hydrogenated polyisoprene star polymers, or hydrogenated diene-styreneblock copolymers, in the “as delivered” polymer concentrate.

Other Antioxidants

Antioxidants retard the oxidative degradation of base oils duringservice. Such degradation may result in deposits on metal surfaces, thepresence of sludge, or a viscosity increase in the lubricant. Oneskilled in the art knows a wide variety of oxidation inhibitors that areuseful in lubricating oil compositions. See, Klamann in Lubricants andRelated Products, op cite, and U.S. Pat. Nos. 4,798,684 and 5,084,197,for example.

Useful antioxidants include hindered phenols. These phenolicantioxidants may be ashless (metal-free) phenolic compounds or neutralor basic metal salts of certain phenolic compounds. Typical phenolicantioxidant compounds are the hindered phenolics which are the oneswhich contain a sterically hindered hydroxyl group, and these includethose derivatives of dihydroxy aryl compounds in which the hydroxylgroups are in the o- or p-position to each other. Typical phenolicantioxidants include the hindered phenols substituted with C₆+ alkylgroups and the alkylene coupled derivatives of these hindered phenols.Examples of phenolic materials of this type 2-t-butyl-4-heptyl phenol;2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;2-methyl-6-t-butyl-4-heptyl phenol; and 2-methyl-6-t-butyl-4-dodecylphenol. Other useful hindered mono-phenolic antioxidants may include forexample hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.Bis-phenolic antioxidants may also be advantageously used in combinationwith the instant disclosure.

Examples of ortho-coupled phenols include:2,2′-bis(4-heptyl-6-t-butyl-phenol); 2,2′-bis(4-octyl-6-t-butyl-phenol);and 2,2′-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenolsinclude for example 4,4′-bis(2,6-di-t-butyl phenol) and4,4′-methylene-bis(2,6-di-t-butyl phenol).

Effective amounts of one or more catalytic antioxidants may also beused. The catalytic antioxidants comprise an effective amount of a) oneor more oil soluble polymetal organic compounds; and, effective amountsof b) one or more substituted N,N′-diaryl-o-phenylenediamine compoundsor c) one or more hindered phenol compounds; or a combination of both b)and c). Catalytic antioxidants are more fully described in U.S. Pat. No.8, 048,833, herein incorporated by reference in its entirety.

Non-phenolic oxidation inhibitors which may be used include aromaticamine antioxidants and these may be used either as such or incombination with phenolics. Typical examples of non-phenolicantioxidants include: alkylated and non-alkylated aromatic amines suchas aromatic monoamines of the formula R⁸R⁹R¹⁰ N where R⁸ is analiphatic, aromatic or substituted aromatic group, R⁹ is an aromatic ora substituted aromatic group, and R¹⁰ is H, alkyl, aryl or R¹¹S(O)xR¹²where R¹¹ is an alkylene, alkenylene, or aralkylene group, R¹² is ahigher alkyl group, or an alkenyl, aryl, or alkaryl group, and x is 0, 1or 2. The aliphatic group R⁸ may contain from 1 to about 20 carbonatoms, and preferably contains from about 6 to 12 carbon atoms. Thealiphatic group is a saturated aliphatic group. Preferably, both R⁸ andR⁹ are aromatic or substituted aromatic groups, and the aromatic groupmay be a fused ring aromatic group such as naphthyl. Aromatic groups R⁸and R⁹ may be joined together with other groups such as S.

Typical aromatic amines antioxidants have alkyl substituent groups of atleast about 6 carbon atoms. Examples of aliphatic groups include hexyl,heptyl, octyl, nonyl, and decyl. Generally, the aliphatic groups willnot contain more than about 14 carbon atoms. The general types of amineantioxidants useful in the present compositions include diphenylamines,phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenylphenylene diamines. Mixtures of two or more aromatic amines are alsouseful. Polymeric amine antioxidants can also be used. Particularexamples of aromatic amine antioxidants useful in the present disclosureinclude: p,p′-dioctyldiphenylamine; t-octylphenyl-alpha-naphthylamine;phenyl-alphanaphthylamine; and p-octylphenyl-alpha-naphthylamine.

Sulfurized alkyl phenols and alkali or alkaline earth metal saltsthereof also are useful antioxidants.

Preferred antioxidants include hindered phenols, arylamines. Theseantioxidants may be used individually by type or in combination with oneanother. Such additives may be used in an amount of about 0.01 to 5weight percent, preferably about 0.01 to 1.5 weight percent, morepreferably zero to less than 1.5 weight percent, more preferably zero toless than 1 weight percent.

Pour Point Depressants (PPDs)

Conventional pour point depressants (also known as lube oil flowimprovers) may be added to the compositions of the present disclosure ifdesired. These pour point depressant may be added to lubricatingcompositions of the present disclosure to lower the minimum temperatureat which the fluid will flow or can be poured. Examples of suitable pourpoint depressants include polymethacrylates, polyacrylates,polyarylamides, condensation products of haloparaffin waxes and aromaticcompounds, vinyl carboxylate polymers, and terpolymers ofdialkylfumarates, vinyl esters of fatty acids and allyl vinyl ethers.U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479;2,666,746; 2,721,877; 2,721,878; and 3,250,715 describe useful pourpoint depressants and/or the preparation thereof. Such additives may beused in an amount of about 0.01 to 5 weight percent, preferably about0.01 to 1.5 weight percent.

Seal Compatibility Agents

Seal compatibility agents help to swell elastomeric seals by causing achemical reaction in the fluid or physical change in the elastomer.Suitable seal compatibility agents for lubricating oils include organicphosphates, aromatic esters, aromatic hydrocarbons, esters (butylbenzylphthalate, for example), and polybutenyl succinic anhydride. Suchadditives may be used in an amount of about 0.01 to 3 weight percent,preferably about 0.01 to 2 weight percent.

Antifoam Agents

Antifoam agents may advantageously be added to lubricant compositions.These agents retard the formation of stable foams. Silicones and organicpolymers are typical antifoam agents. For example, polysiloxanes, suchas silicon oil or polydimethyl siloxane, provide antifoam properties.Antifoam agents are commercially available and may be used inconventional minor amounts along with other additives such asdemulsifiers; usually the amount of these additives combined is lessthan 1 weight percent and often less than 0.1 weight percent.

Inhibitors and Antirust Additives

Antirust additives (or corrosion inhibitors) are additives that protectlubricated metal surfaces against chemical attack by water or othercontaminants. A wide variety of these are commercially available.

One type of antirust additive is a polar compound that wets the metalsurface preferentially, protecting it with a film of oil. Another typeof antirust additive absorbs water by incorporating it in a water-in-oilemulsion so that only the oil touches the metal surface. Yet anothertype of antirust additive chemically adheres to the metal to produce anon-reactive surface. Examples of suitable additives include zincdithiophosphates, metal phenolates, basic metal sulfonates, fatty acidsand amines. Such additives may be used in an amount of about 0.01 to 5weight percent, preferably about 0.01 to 1.5 weight percent.

Antiwear Additives

A metal alkylthiophosphate and more particularly a metal dialkyl dithiophosphate in which the metal constituent is zinc, or zinc dialkyl dithiophosphate (ZDDP) can be a useful component of the lubricating oils ofthis disclosure. ZDDP can be derived from primary alcohols, secondaryalcohols or mixtures thereof. ZDDP compounds generally are of theformula

Zn[SP(S)(OR¹)(OR²)]₂

where R¹ and R² are C₁-C₁₈ alkyl groups, preferably C₂-C₁₂ alkyl groups.These alkyl groups may be straight chain or branched. Alcohols used inthe ZDDP can be propanol, 2-propanol, butanol, secondary butanol,pentanols, hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol,2-ethyl hexanol, alkylated phenols, and the like. Mixtures of secondaryalcohols or of primary and secondary alcohol can be preferred. Alkylaryl groups may also be used.

Preferable zinc dithiophosphates which are commercially availableinclude secondary zinc dithiophosphates such as those available from forexample, The Lubrizol Corporation under the trade designations “LZ677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite underthe trade designation “OLOA 262” and from for example Afton Chemicalunder the trade designation “HITEC 7169”.

The ZDDP is typically used in amounts of from about 0.3 weight percentto about 1.5 weight percent, preferably from about 0.4 weight percent toabout 1.2 weight percent, more preferably from about 0.5 weight percentto about 1.0 weight percent, and even more preferably from about 0.6weight percent to about 0.8 weight percent, based on the total weight ofthe lubricating oil, although more or less can often be usedadvantageously. Preferably, the ZDDP is a secondary ZDDP and present inan amount of from about 0.6 to 1.0 weight percent of the total weight ofthe lubricating oil.

Friction Modifiers

A friction modifier is any material or materials that can alter thecoefficient of friction of a surface lubricated by any lubricant orfluid containing such material(s). Friction modifiers, also known asfriction reducers, or lubricity agents or oiliness agents, and othersuch agents that change the ability of base oils, formulated lubricantcompositions, or functional fluids, to modify the coefficient offriction of a lubricated surface may be effectively used in combinationwith the base oils or lubricant compositions of the present disclosureif desired. Friction modifiers that lower the coefficient of frictionare particularly advantageous in combination with the base oils and lubecompositions of this disclosure.

Illustrative friction modifiers may include, for example, organometalliccompounds or materials, or mixtures thereof. Illustrative organometallicfriction modifiers useful in the lubricating engine oil formulations ofthis disclosure include, for example, molybdenum amine, molybdenumdiamine, an organotungstenate, a molybdenum dithiocarbamate, molybdenumdithiophosphates, molybdenum amine complexes, molybdenum carboxylates,and the like, and mixtures thereof. Similar tungsten based compounds maybe preferable.

Other illustrative friction modifiers useful in the lubricating engineoil formulations of this disclosure include, for example, alkoxylatedfatty acid esters, alkanolamides, polyol fatty acid esters, boratedglycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.

Illustrative alkoxylated fatty acid esters include, for example,polyoxyethylene stearate, fatty acid polyglycol ester, and the like.These can include polyoxypropylene stearate, polyoxybutylene stearate,polyoxyethylene isosterate, polyoxypropylene isostearate,polyoxyethylene palmitate, and the like.

Illustrative alkanolamides include, for example, lauric aciddiethylalkanolamide, palmic acid diethylalkanolamide, and the like.These can include oleic acid diethyalkanolamide, stearic aciddiethylalkanolamide, oleic acid diethylalkanolamide, polyethoxylatedhydrocarbylamides, polypropoxylated hydrocarbylamides, and the like.

Illustrative polyol fatty acid esters include, for example, glycerolmono-oleate, saturated mono-, di-, and tri-glyceride esters, glycerolmono-stearate, and the like. These can include polyol esters,hydroxyl-containing polyol esters, and the like.

Illustrative borated glycerol fatty acid esters include, for example,borated glycerol mono-oleate, borated saturated mono-, di-, andtri-glyceride esters, borated glycerol mono-sterate, and the like. Inaddition to glycerol polyols, these can include trimethylolpropane,pentaerythritol, sorbitan, and the like. These esters can be polyolmonocarboxylate esters, polyol dicarboxylate esters, and on occasionpolyoltricarboxylate esters. Preferred can be the glycerol mono-oleates,glycerol dioleates, glycerol trioleates, glycerol monostearates,glycerol distearates, and glycerol tristearates and the correspondingglycerol monopalmitates, glycerol dipalmitates, and glyceroltripalmitates, and the respective isostearates, linoleates, and thelike. On occasion the glycerol esters can be preferred as well asmixtures containing any of these. Ethoxylated, propoxylated, butoxylatedfatty acid esters of polyols, especially using glycerol as underlyingpolyol can be preferred.

Illustrative fatty alcohol ethers include, for example, stearyl ether,myristyl ether, and the like. Alcohols, including those that have carbonnumbers from C₃ to C₅₀, can be ethoxylated, propoxylated, or butoxylatedto form the corresponding fatty alkyl ethers. The underlying alcoholportion can preferably be stearyl, myristyl, C₁₁-C₁₃ hydrocarbon, oleyl,isosteryl, and the like.

The lubricating oils of this disclosure exhibit desired properties,e.g., wear control, in the presence or absence of a friction modifier.

Useful concentrations of friction modifiers may range from 0.01 weightpercent to 5 weight percent, or about 0.1 weight percent to about 2.5weight percent, or about 0.1 weight percent to about 1.5 weight percent,or about 0.1 weight percent to about 1 weight percent. Concentrations ofmolybdenum-containing materials are often described in terms of Mo metalconcentration. Advantageous concentrations of Mo may range from 25 ppmto 700 ppm or more, and often with a preferred range of 50-200 ppm.Friction modifiers of all types may be used alone or in mixtures withthe materials of this disclosure. Often mixtures of two or more frictionmodifiers, or mixtures of friction modifier(s) with alternate surfaceactive material(s), are also desirable.

The types and quantities of performance additives used in combinationwith the instant disclosure in lubricant compositions are not limited bythe examples shown herein as illustrations.

When lubricating oil compositions contain one or more of the additivesdiscussed above, the additive(s) are blended into the composition in anamount sufficient for it to perform its intended function. Typicalamounts of such additives useful in the present disclosure are shown inTable 1 below.

It is noted that many of the additives are shipped from the additivemanufacturer as a concentrate, containing one or more additivestogether, with a certain amount of base oil diluents. Accordingly, theweight amounts in the table below, as well as other amounts mentionedherein, are directed to the amount of active ingredient (that is thenon-diluent portion of the ingredient). The weight percent (wt %)indicated below is based on the total weight of the lubricating oilcomposition.

When lubricating oil compositions contain one or more of the additivesdiscussed above, the additive(s) are blended into the composition in anamount sufficient for it to perform its intended function. Typicalamounts of such additives useful in the present disclosure are shown inTable 1 below.

It is noted that many of the additives are shipped from the additivemanufacturer as a concentrate, containing one or more additivestogether, with a certain amount of base oil diluents. Accordingly, theweight amounts in the table below, as well as other amounts mentionedherein, are directed to the amount of active ingredient (that is thenon-diluent portion of the ingredient). The weight percent (wt %)indicated below is based on the total weight of the lubricating oilcomposition.

TABLE 1 Typical Amounts of Other Lubricating Oil Components ApproximateApproximate Compound wt % (Useful) wt % (Preferred) Dispersant 0.1-20 0.1-8   Detergent 0.1-20  0.1-8   Friction Modifier 0.01-5   0.01-1.5 Antioxidant 0.1-5   0.1-1.5 Pour Point Depressant 0.0-5   0.01-1.5 (PPD) Antifoam Agent 0.001-3    0.001-0.15  Viscosity Modifier (solid0.1-2   0.1-1   polymer basis) Antiwear 0.2-3   0.5-1   Inhibitor andAntirust 0.01-5   0.01-1.5 

The foregoing additives are all commercially available materials. Theseadditives may be added independently but are usually precombined inpackages which can be obtained from suppliers of lubricant oiladditives. Additive packages with a variety of ingredients, proportionsand characteristics are available and selection of the appropriatepackage will take the requisite use of the ultimate composition intoaccount.

The following non-limiting examples are provided to illustrate thedisclosure.

EXAMPLES

Lubricating oils were prepared as described herein. All of theingredients used herein are commercially available.

The additive package used in the lubricating oils included conventionaladditives in conventional amounts. Conventional additives used in theformulations were one or more of a dispersant, pour point depressant,detergent, corrosion inhibitor, metal deactivator, seal compatibilityadditive, inhibitor, and anti-rust additive.

The lubricant oils prepared herein were tested in accordance with theLubricant Oxidation Test (also referred to as the Oxidation StabilityTest (OST) and the 210 Hours Lubricant Oxidation Test) as describedherein, and the Catalytic Oxidation Test (also referred to as the B10Oxidation Test), as described herein.

The Lubricant Oxidation Test involved loading a vial with 10 mL ofsample, and 50 ppm of Fe in an oil soluble form. There was a headpressure of air of 50 psi, and air was bubbled in the vial at 125ml/min. The test was run maintaining the temperature at 170° C. and, ata pre-determined interval, a small aliquot of the sample was taken outto measure the viscosity at 40° C. The measurement of the viscosity at40° C. was similar to ASTM D445 and the results comparable. Once theviscosity increases over 200% compared to the initial viscosity, the oilwas considered condemned. The Lubricant Oxidation Test (time to 200%KV40 increase) was used to quantify the oxidative stability of theinventive and comparative oil compositions.

The Catalytic Oxidation Test involved bubbling a stream of air through avolume of the lubricant at the rate of five liters per hour, in presenceof metal catalyst coupons (lead, copper, iron), at 165° C. for 40 hoursand/or at 218° C. for 24 hours. The end of test viscosity at 100° C. wascompared to initial lubricant viscosity at 100° C. The percent viscosityincrease was used to quantify the oxidative stability of the inventiveand comparative oil compositions.

Quercetin was esterified with 2-hexyldecanoic acid according to thefollowing reaction scheme.

In the above reaction, a molar ratio of quercetin:2-hexyldecanoic acidof 1:2 gave the following:

Further, in the above reaction, a molar ratio ofquercetin:2-hexyldecanoic acid of 1:3 gave the following:

In the reaction for the preparation of functionalized quercetin at amolar ratio of quercetin:2-hexyldecanoic acid of 1:3 (Inventive Example2), the starting materials listed below were used in accordance with theprocedure described below.

Starting 

 Material 

MW 

 (g/mol) 

Mass 

 (g) 

 /Vol 

mmol 

Quercetin 

302.24 

 3.000 

 9.93 

2 

 Hexyldecanoic Acid 

256.43 

 7.020 

27.38 

N-(3-Dimethylaminopropyl)- 191.70 

 8.940 

46.64 

N 

 ethylcarbodiimide

hydrochloride 

 (EDC 

 HCl) 

 Catalyst 

4-(Dimethylamino)pyridine

 (DMAP) 

 Catalyst 

122.17 

 3.760 

30.78 

Dichloromethane, anhydrous 

 Solvent 

200 mL 

indicates data missing or illegible when filed

To a stirring room temperature mixture of quercetin (3.00 g, 9.93 mmol)and 2-hexyldecanoic acid (7.02 g, 27.38 mmol, 2.75 equiv.) indichloromethane (200 mL) was added EDC*HCl (8.94 g, 46.64 mmol, 4.70equiv.) followed by DMAP (3.76 g, 30.78 mmol, 3.10 equiv.) The mixturewas placed under nitrogen and stirred at room temperature overnight,during which time the mixture changed from a yellow suspension to abrown liquid solution. The progress of the reaction was monitored bythin-layer chromatography (TLC) using 10% ethyl acetate in hexanes (v/v)as developing solvent. Upon complete consumption of the 2-hexyldecanoicacid by TLC, the reaction mixture was diluted with dichloromethane(approx. 300 mL), transferred to a separatory funnel, and washed with10% KHSO4 (3×200 mL) followed by water and brine. The organic layer wascollected, dried over Na2SO4, isolated and concentrated in vacuum toafford a viscous brown liquid. 1H and 13C NMR spectra were acquired ofthe crude product mixture, which showed unknown signals in the 2.5-4 ppmrange for 1H NMR. The crude material was redissolved in dichloromethane,transferred to a separatory funnel, and washed with 10% KHSO4 (3×150 mL)followed by water and brine. The organic material was dried over Na2SO4,isolated and concentrated in vacuum to give a viscous brown liquid (3.1g, ˜33% yield). 1H NMR spectrum was obtained and indicated impuritieswere still present in the final product. FIG. 4 shows the 1H and 13C NMRof Inventive Example 2.

The same procedure is applicable to the synthesis of the functionalizedquercetin at a molar ratio of quercetin:2-hexyldecanoic acid of 1:2(Inventive Example 1).

Quercetin was esterified with mPAO S-propionic acid according to thefollowing reaction scheme.

In the reaction for the preparation of functionalized quercetinesterified with mPAO S-propionic acid (Inventive Example 3), the mPAOS-propionic acid was prepared with the starting materials listed belowand in accordance with the procedure described below.

Compound 

MW 

 (g/mol) 

Wt/vol 

mmol 

Ratio 

Unhydrogenated mPAO 

 991.6 

50.0 

50.4 

1.0 

3-Mercaptopropionic acid 

  106.1 

 6.96 

65.6 

1.3 

2,2-dimethoxy-2-   256.3 

 0.26 

 1.01 

0.02 

phenylacetophenone (DMPA) 

 catalyst 

Methylene 

 chloride 

25 

indicates data missing or illegible when filed

To a stirred solution of unhydrogenated mPAO (Run 5, MIDAS #16-071066)(Mn ˜991.55 g/mol, 50.00 g, 50.426 mmol) in CH2Cl2 (25 ml) in acolorless glass bottle was added 3-mercaptopropionic acid (6.9582 g,65.554 mmol, 1.30 equiv.), and 2,2-dimethoxy-2-phenylacetophenone(0.2585 g, 1.009 mmol, 0.020 equiv.). The resulting mixture was flushedwith nitrogen and irradiated with a UV lamp (4 W, 365 nm) at roomtemperature. After 120 minutes of UV irradiation, the 1HNMR showedincomplete reaction. Additional 0.20 g of DMPA was added, and thereaction was continued UV for additional 120 min. 1HNMR showed thereaction was almost complete. Total UV time: (120+120) min=4 hr. Theresulting homogeneous colorless solution was diluted with CH2Cl2, washedwith water (3×150 ml) and brine (100 ml). The organic layer wasseparated, dried over MgSO4, filtered and concentrated on a rotaryevaporator under vacuum to afford a colorless liquid as crude product(51.54 g). Midas #17-016043.

In the reaction for the preparation of functionalized quercetinesterified with mPAO S-propionic acid (Inventive Example 3), thestarting materials listed below were used in accordance with theprocedure described below.

Compound 

MW 

 (g/mol) 

Wt./vol 

mmol 

Ratio 

Quercetin 

   302.2 

 1.6 

 5.3 

1.0 

mPAO 

 propionic acid 

 1097.7 

 13.1 

11.9 

2.3 

N-(3-Dimethylaminopropyl)-N 

 ethylcarbodiimide    191.7 

 3.9 

20.1 

3.8 

hydrochloride 

 (EDC 

 HCl) 

 catalyst 

4-(Dimethylamino)pyridine(DMAP) 

 catalyst 

   122.2 

 1.6 

13.5 

2.6 

Methylene 

 chloride 

125 

indicates data missing or illegible when filed

To a stirred mixture of quercetin (1.60 g, 5.2938 mmol), mPAOS-propionic acid (Midas #17-016043, 13.075 g, 11.911 mmol, 2.25 equiv.)in CH2Cl2 (125 ml) was added EDC*HCl (3.8563 g, 20.116 mmol, 3.8 equiv.)and DMAP (1.6492 g, 13.499 mmol, 2.55 equiv.) at room temperature. Themixture was then kept stirring at room temperature under nitrogenatmosphere overnight. The progress of the reaction was monitored by thinlayer chromatography (TLC) using hexane/ethyl acetate as eluent. Uponcomplete consumption of the mPAO S-propionic acid starting material, thereaction mixture was diluted with CH2Cl2 (175 mL), transferred to aseparatory funnel, and washed with 10% KHSO4 (3×200 ml), water andbrine. The organic layer was collected, dried over MgSO4, andconcentrated in vacuum to afford a viscous brown liquid crude product(8.6 g). 1H NMR was acquired on the crude product mixture and comparedwith that of starting material. Midas #17-028646. FIG. 5 shows the 1HNMR of Inventive Example 3.

Referring to FIGS. 1-3, the functionalized quercetin designatedInventive Example 1 is represented by the following formula:

Referring to FIGS. 1-3, the functionalized quercetin designatedInventive Example 2 is represented by the following formula:

Referring to FIGS. 1-3, the functionalized quercetin designatedInventive Example 3 is represented by the following formula:

The functionalized quercetin antioxidants can provide equivalent orbetter performance than commercially available phenolic or aminicantioxidants. The functionalized quercetin to antioxidants have shownsimilar activity at lower treat rate and were found to be particularlyeffective when used in conjunction with aminic antioxidants asillustrated by the Lubricant Oxidation Test results in an industrial oilformulation, as graphically shown in FIG. 1. The Lubricant OxidationTest results in FIG. 1 were at 165° C., 125 cc/min. air in presence ofCu naphthenate.

Relative performance of functionalized quercetin samples was assessedagainst the performance of commercial phenolic antioxidant, Irganox L135[6-methylheptyl 3-(3,5-di-tertbutyl-4-hydroxyphenyl) propionate] inindustrial oil formulation using the Catalytic Oxidation Test run for 40hours at 163° C. and 24 hours at 218° C. Better than equivalentperformance, as shown by the viscosity increase, was observed for thefunctionalized quercetin samples at much lower treat rate (see FIG. 2).FIG. 2 shows comparative Catalytic Oxidation Test results offunctionalized quercetin samples relative to commercial phenolicantioxidant.

A direct comparison of functionalized quercetin samples to thecommercial aminic antioxidant, Irganox L57 (octylated diphenyl amine) isshown in FIG. 3. FIG. 3 shows better to equivalent performance achievedfor the functionalized quercetin samples at much lower treat rate. FIG.3 shows comparative Catalytic Oxidation Test results of functionalizedquercetin samples relative to commercial aminic antioxidant.

PCT and EP Clauses:

1. A lubricating oil having a composition comprising a lubricating oilbase stock as a major component, and at least one functionalizedquercetin antioxidant, as a minor component; wherein the functionalizedquercetin antioxidant has the following structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

2. The lubricating oil of clause 1 wherein the at least onefunctionalized quercetin antioxidant is soluble in the lubricating oil;and wherein, in an engine or other mechanical component lubricated withthe lubricating oil, antioxidant performance is improved or maintainedas compared to antioxidant performance achieved using a lubricating oilcontaining a phenolic or aminic antioxidant, as determined by LubricantOxidation Test or Catalytic Oxidation Test.

3. The lubricating oil of clauses 1 and 2 wherein the functionalizedquercetin antioxidant comprises a partially esterified quercetin or apartially etherified quercetin.

4. The lubricating oil of clauses 1-3 wherein the functionalizedquercetin antioxidant comprises the reaction product of quercetin with acarboxylic acid.

5. The lubricating oil of clause 1-3 wherein the functionalizedquercetin antioxidant comprises the reaction product of quercetin with2-hexyldecanoic acid, wherein the molar ratio ofquercetin:2-hexyldecanoic acid is 1:2 or 1:3.

6. The lubricating oil of clause 1-3 wherein the functionalizedquercetin antioxidant comprises the reaction product of quercetin withmPAO S-propionic acid.

7. The lubricating oil of clause 1-3 wherein the functionalizedquercetin antioxidant comprises the reaction product of quercetin withbrominated atactic polypropylene (aPP).

8. The lubricating oil of clause 1-7 wherein the functionalizedquercetin antioxidant is selected from the group having the formula

9. The lubricating oil of clause 1-8 wherein the lubricating oil basestock comprises a Group I, Group II, Group III, Group IV or Group V baseoil.

10. The lubricating oil of clause 1-9 wherein the functionalizedquercetin antioxidant is present in an amount from 0.01 to 5 weightpercent, based on the total weight of the formulated oil.

11. The lubricating oil of clauses 1-10 wherein the lubricating oil basestock is present in an amount of from 50 weight percent to 95 weightpercent, based on the total weight of the formulated oil.

12. The lubricating oil of clauses 1-11 further comprising one or moreaminic antioxidants.

13. A method for improving or maintaining antioxidant performance of alubricating oil in an engine or other mechanical component lubricatedwith lubricating oil by using as the lubricating oil a formulated oil,said formulated oil having a composition comprising a lubricating oilbase stock as a major component, and at least one functionalizedquercetin antioxidant, as a minor component; wherein the functionalizedquercetin antioxidant has the following structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen.

14. A composition comprising functionalized quercetin.

15. A process for preparing functionalized quercetin, said processcomprising esterifying or etherifying quercetin under reactionconditions sufficient to prepare the functionalized quercetin.

All patents and patent applications, test procedures (such as ASTMmethods, UL methods, and the like), and other documents cited herein arefully incorporated by reference to the extent such disclosure is notinconsistent with this disclosure and for all jurisdictions in whichsuch incorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.While the illustrative embodiments of the disclosure have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of thedisclosure. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present disclosure,including all features which would be treated as equivalents thereof bythose skilled in the art to which the disclosure pertains.

The present disclosure has been described above with reference tonumerous embodiments and specific examples. Many variations will suggestthemselves to those skilled in this art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims.

1. A lubricating oil having a composition comprising a lubricating oilbase stock as a major component, and at least one functionalizedquercetin antioxidant, as a minor component; wherein the functionalizedquercetin antioxidant has the following structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen. 2.The lubricating oil of claim 1 wherein the at least one functionalizedquercetin antioxidant is soluble in the lubricating oil; and wherein, inan engine or other mechanical component lubricated with the lubricatingoil, antioxidant performance is improved or maintained as compared toantioxidant performance achieved using a lubricating oil containing aphenolic or aminic antioxidant, as determined by Lubricant OxidationTest or Catalytic Oxidation Test.
 3. The lubricating oil of claim 1wherein the functionalized quercetin antioxidant comprises a partiallyesterified quercetin or a partially etherified quercetin.
 4. Thelubricating oil of claim 1 wherein the functionalized quercetinantioxidant comprises the reaction product of quercetin with acarboxylic acid.
 5. The lubricating oil of claim 1 wherein thefunctionalized quercetin antioxidant comprises the reaction product ofquercetin with 2-hexyldecanoic acid, wherein the molar ratio ofquercetin:2-hexyldecanoic acid is 1:2 or 1:3.
 6. The lubricating oil ofclaim 1 wherein the functionalized quercetin antioxidant comprises thereaction product of quercetin with mPAO S-propionic acid.
 7. Thelubricating oil of claim 1 wherein the functionalized quercetinantioxidant comprises the reaction product of quercetin with brominatedatactic polypropylene (aPP).
 8. The lubricating oil of claim 1 whereinthe functionalized quercetin antioxidant is selected from the grouphaving the formula


9. The lubricating oil of claim 1 wherein the lubricating oil base stockcomprises a Group I, Group II, Group III, Group IV or Group V base oil.10. The lubricating oil of claim 1 wherein the functionalized quercetinantioxidant is present in an amount from 0.01 to 5 weight percent, basedon the total weight of the formulated oil.
 11. The lubricating oil ofclaim 1 wherein the lubricating oil base stock is present in an amountof from 50 weight percent to 95 weight percent, based on the totalweight of the formulated oil.
 12. The lubricating oil of claim 1 furthercomprising one or more aminic antioxidants.
 13. The lubricating oil ofclaim 1 further comprising one or more of an antiwear additive,viscosity modifier, detergent, dispersant, pour point depressant, metaldeactivator, seal compatibility additive, inhibitor, and anti-rustadditive.
 14. A method for improving or maintaining antioxidantperformance of a lubricating oil in an engine or other mechanicalcomponent lubricated with lubricating oil by using as the lubricatingoil a formulated oil, said formulated oil having a compositioncomprising a lubricating oil base stock as a major component, and atleast one functionalized quercetin antioxidant, as a minor component;wherein the functionalized quercetin antioxidant has the followingstructural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen. 15.The method of claim 14 wherein the at least one functionalized quercetinantioxidant is soluble in the lubricating oil; and wherein antioxidantperformance is improved or maintained as compared to antioxidantperformance achieved using a lubricating oil containing a phenolic oraminic antioxidant, as determined by Lubricant Oxidation Test orCatalytic Oxidation Test.
 16. The method of claim 14 wherein thefunctionalized quercetin antioxidant comprises partially esterifiedquercetin or a partially etherified quercetin.
 17. The method of claim14 wherein the functionalized quercetin antioxidant comprises thereaction product of quercetin with a carboxylic acid.
 18. The method ofclaim 14 wherein the functionalized quercetin antioxidant comprises thereaction product of quercetin with 2-hexyldecanoic acid, wherein themolar ratio of quercetin:2-hexyldecanoic acid is 1:2 or 1:3.
 19. Themethod of claim 14 wherein the functionalized quercetin antioxidantcomprises the reaction product of quercetin with mPAO S-propionic acid.20. The method of claim 14 wherein the functionalized quercetinantioxidant comprises the reaction product of quercetin with brominatedatactic polypropylene (aPP).
 21. The method of claim 14 wherein thefunctionalized quercetin antioxidant is selected from the group havingthe formula


22. The method of claim 14 wherein the lubricating oil base stockcomprises a Group I, Group II, Group III, Group IV or Group V base oil.23. The method of claim 14 wherein the functionalized quercetinantioxidant is present in an amount from 0.01 to 5 weight percent, basedon the total weight of the lubricating oil.
 24. The method of claim 14wherein the lubricating oil base stock is present in an amount of from50 weight percent to 95 weight percent, based on the total weight of thelubricating oil.
 25. The method of claim 14 wherein the lubricating oilfurther comprises one or more aminic antioxidants.
 26. The method ofclaim 14 wherein the lubricating oil further comprises one or more of anantiwear additive, viscosity modifier, detergent, dispersant, pour pointdepressant, metal deactivator, seal compatibility additive, inhibitor,and anti-rust additive.
 27. The method of claim 14 wherein thelubricating oil is a passenger vehicle engine oil (PVEO) or a commercialvehicle engine oil (CVEO).
 28. A composition comprising functionalizedquercetin.
 29. The composition of claim 28 wherein the functionalizedquercetin has the following structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen. 30.The composition of claim 28 which comprises partially esterifiedquercetin or a partially etherified quercetin.
 31. The composition ofclaim 28 which comprises the reaction product of quercetin with acarboxylic acid.
 32. The composition of claim 28 which comprises thereaction product of quercetin with 2-hexyldecanoic acid, wherein themolar ratio of quercetin:2-hexyldecanoic acid is 1:2 or 1:3.
 33. Thecomposition of claim 28 which comprises the reaction product ofquercetin with mPAO S-propionic acid.
 34. The composition of claim 28wherein the functionalized quercetin comprises the reaction product ofquercetin with brominated atactic polypropylene (aPP).
 35. Thecomposition of claim 28 which is selected from the group having theformula


36. The composition of claim 28 which is an antioxidant.
 37. Thecomposition of claim 36 further comprising one or more aminicantioxidants.
 38. The composition of claim 36 which is soluble in alubricating oil.
 39. A process for preparing functionalized quercetin,said process comprising esterifying or etherifying quercetin underreaction conditions sufficient to prepare the functionalized quercetin.40. The process of claim 39 wherein the functionalized quercetin has thefollowing structural formula:

wherein each R is independently hydrogen, alkyl group, sulfur or oxygencontaining alkyl group, alkylated acyl group, or sulfur or oxygencontaining alkylated acyl group, with the proviso that at least two Rgroups are hydrogen and at least one R group is other than hydrogen. 41.The process of claim 39 wherein the functionalized quercetin comprisespartially esterified quercetin or a partially etherified quercetin. 42.The process of claim 39 wherein the functionalized quercetin comprisesthe reaction product of quercetin with a carboxylic acid.
 43. Theprocess of claim 39 wherein the functionalized quercetin comprises thereaction product of quercetin with 2-hexyldecanoic acid, wherein themolar ratio of quercetin:2-hexyldecanoic acid is 1:2 or 1:3.
 44. Theprocess of claim 39 wherein the functionalized quercetin comprises thereaction product of quercetin with mPAO S-propionic acid.
 45. Theprocess of claim 39 wherein the functionalized quercetin comprises thereaction product of quercetin with brominated atactic polypropylene(aPP).
 46. The process of claim 39 wherein the functionalized quercetinis selected from the group having the formula


47. The process of claim 39 wherein the functionalized quercetin is anantioxidant.
 48. The process of claim 39 wherein the functionalizedquercetin is soluble in a lubricating oil.